US HEAVY CRUISERS 1941–45 Pre-war Classes MARK STILLE ILLUSTRATED BY PAUL WRIGHT © Osprey Publishing • www.ospreypublishing.com NEW VANGUARD 210 US HEAVY CRUISERS 1941–45 Pre-war Classes MARK STILLE ILLUSTRATED BY PAUL WRIGHT © Osprey Publishing • www.ospreypublishing.com CONTENTS INTRODUCTION 4 NAVAL STRATEGY AND THE ROLE OF THE HEAVY CRUISER 4 USN HEAVY CRUISER DESIGN AND THE NAVAL TREATIES 6 USN HEAVY CRUISER WEAPONS 8 USN HEAVY CRUISER RADAR 10 PENSACOLA CLASS 11 t Design and Construction t Armament t Service Modifications t Wartime Service NORTHAMPTON CLASS 17 t Design and Construction t Armament t Service Modifications t Wartime Service PORTLAND CLASS 25 t Design and Construction t Armament t Service Modifications t Wartime Service NEW ORLEANS CLASS 30 t Design and Construction t Armament t Service Modifications t Wartime Service WICHITA CLASS 42 t Design and Construction t Armament t Service Modifications t Wartime Service ANALYSIS AND CONCLUSION 45 BIBLIOGRAPHY 47 INDEX 48 © Osprey Publishing • www.ospreypublishing.com US HEAVY CRUISERS 1941–45 PRE-WAR CLASSES INTRODUCTION In the interwar period, the United States Navy (USN) built 18 large cruisers. These came to be known as “heavy cruisers” because of their size and later because of their armament. All of these ships were built under limitations resulting from a series of naval treaties, and thus they were also known as “treaty cruisers.” These ships gave valuable service during World War II and saw action in all the major battles in the Pacific. A separate volume will cover the heavy cruisers built during and after the war that saw service not only in 1941–45, but also later in the Korean and Vietnam conflicts. AMERICAN NAVAL STRATEGY AND THE ROLE OF THE HEAVY CRUISER The heavy cruiser was a staple in the USN during World War II. The term came into use in 1920 to distinguish it from a light cruiser in terms of size and importance. In 1931, the use of the term was clarified and applied to any cruiser with 8in guns. Traditionally, American cruisers were seen primarily as US Navy heavy cruisers were the centerpiece of the pre-war Scouting Force. Here, four ships turn in formation to create a ‘slick’ for landing their floatplanes off Pearl Harbor in 1933. From inboard to outboard are Chicago, Louisville, Salt Lake City, and Northampton. (NHHC) 4 © Osprey Publishing • www.ospreypublishing.com scouting ships in support of the main battle fleet and, in addition, were tasked This pre-war view shows Salt to counter enemy scouting forces and screen the battle fleet. Their speed and Lake City in the foreground, range also made them well suited as commerce raiders or for protecting with Northampton, Portland, Louisville, and Chester in shipping lanes against enemy raiders. formation. Operating together The Washington Naval Treaty of 1922 magnified the importance of heavy in this fashion, heavy cruisers cruisers. Since the treaty placed limits on the number of battleships that the formed powerful strike groups USN could operate but not on heavy cruisers, the latter became a substitute that were used for a variety of missions when the war began. for the battleship. The smaller number of battleships meant that they were (NARA) less likely to be risked, especially on secondary missions. In their place, heavy cruisers were an obvious substitute. Going into the Pacific War, heavy cruisers were assigned to the Fleet Scouting Force, which reflected their primary mission. In addition to their scouting mission in support of the battle fleet, heavy cruisers were assigned as escorts to the Pacific Fleet’s carriers. This was a natural fit, since the heavy cruiser had the speed and endurance to keep up with the carriers, but it was also seen as necessary to protect the carriers from Japanese cruisers or battlecruisers. The heavy cruiser also possessed a relatively heavy antiaircraft fit that could help protect the carrier from air attack. At the start of the Pacific War, the importance of the cruiser was immediately elevated. The attack on Pearl Harbor reduced the strength of the USN’s battle line and demonstrated that the war would not be fought between opposing battle fleets, but that carrier aviation would be dominant. The vulnerability of older USN battleships to torpedo damage was also clearly in evidence. As the carrier became the center of American naval operations, the heavy cruiser became an integral part of carrier task forces. Cruisers were the primary escorts for the carriers during the series of early war carrier raids between February and April 1942, and during the first two carrier battles in the Coral Sea in May and at Midway in June. When the focus of operations in the Pacific shifted to the South Pacific, beginning in August 1942, the heavy cruiser assumed another role as the leading element of surface task forces committed to engaging the Japanese Navy at night in the waters around Guadalcanal. From August until November, there were five major battles against the Japanese, with American heavy cruisers being the centerpiece of the American task forces in all but one. Against the well-drilled Japanese, who had spent considerable time and 5 © Osprey Publishing • www.ospreypublishing.com The two cruisers to the left are the first-generation treaty cruisers Salt Lake City and Pensacola. Inboard of them is the third-generation New Orleans. This photograph was taken at Pearl Harbor on October 32, 1943, and shows clearly the differences between the generations. The low freeboard of the first- generation ships is obvious, as is their top-heavy appearance with the large tripod foremasts. (NHHC) resources developing and practicing night-fighting doctrine and equipment, the American heavy cruisers suffered severely. The extent of the carnage is shown by the fact that of the 14 heavy cruisers active during the campaign for Guadalcanal, five were sunk and another seven damaged. After the struggle for Guadalcanal concluded with an American victory in February 1943, USN heavy cruisers continued to take a prominent role in the advance to Japan. Given additional antiaircraft weaponry, they continued to perform admirably as carrier escorts. They showed their versatility as they were employed in a number of roles, including shore bombardment and engaging Japanese surface units when the opportunity was presented. Heavy cruisers also were active in the European theater in convoy escort and shore bombardment roles. By the end of the war, seven of the 18 treaty heavy cruisers had been sunk, but victory had been secured. USN HEAVY CRUISER DESIGN AND THE IMPACT OF THE WASHINGTON AND LONDON NAVAL TREATIES Coming out of World War I, the USN planned a massive expansion. Part of this would be the construction of a large number of cruisers to screen the battle line and the battlecruiser force, and to form forces dedicated to scouting and providing protection from enemy scouting forces. The most likely opponent was judged to be the Japanese, but the USN was also driven to gain parity with the Royal Navy. Originally, the cruiser design to fill these needs was based on the Omaha- class scout cruiser; a 7,100t ship armed with 12 6in guns and a top speed of 35kt. This changed with the ratification of the Washington Naval Treaty in February 1922. Because it thought a larger cruiser was required for the 6 © Osprey Publishing • www.ospreypublishing.com expanses of the Pacific, the USN was happy with the limitations on cruisers contained in the treaty, which were set at 10,000t with a gun no greater than 8in. While there were limits on individual ships, there was no limit set on the overall tonnage or number of cruisers that each power could build. For the USN, the upper limit of cruiser size became the standard design size for all. Since the Americans did not want to build ships with inferior armament to foreign contemporaries, 8in main batteries also became the norm. Since the treaty set limits on battleship tonnage for the world’s five principal navies, and none was set for cruisers, a cruiser building spree quickly ensued. In late 1922, the USN planned to finish the construction of the ten planned Omaha-class cruisers and 16 new 8in cruisers. However, Congress was reluctant to fund what it saw as excessive requests and, during the interwar period, the USN was tardy building up to its allowed limits. This view, taken in 1936, shows With evidence of Japanese heavy cruiser construction, Congress approved the differences between the eight cruisers in late 1924, but funded only two. The other six were not second- and third-generation funded until 1926 and 1927. treaty cruisers. Tuscaloosa (New Orleans class) is alongside the The first American heavy cruiser designs under the Washington Treaty pier with Chicago outboard. favored firepower and speed over protection. The first generation of treaty Note the different 8in turrets cruisers were called ‘tinclads’ because of their sparse armor. These ships and the different aft of the Pensacola and Northampton classes were well under the 10,000t superstructure. Chicago has a treaty limitation, and therefore were not well-balanced designs. After a large tripod mainmast aft while the aft part of Tuscaloosa’s transitional design of the two ships of the Portland class, American designers superstructure is the aircraft hit their stride with the much more successful New Orleans class. These hangar. (NHHC) seven ships were well protected and maintained a high speed and powerful main and secondary batteries. Since the Washington Naval Treaty imposed no limit on the numbers of cruisers that could be built, the primary goal of the London Naval Conference, opened in January 1930, was to place a cap on cruiser construction.